Benjamin Nketia-Yawson이효상손해정김봉수노용영2016-01-04T17:00:04Z2016-01-04T17:00:04Z2016021566119946010http://pubs.kist.re.kr/handle/201004/58350We report high-performance organic thin-film transistors (OTFTs) with an ultrathin active layer of difluorobenzothiadiazole-dithienosilole copolymer (PDFDT) form by using the wire bar-coating process. The top-gate/bottom contact (TG/BC) OTFTs based on bar-coated PDFDT polymer as channel material and poly(methyl methacrylate) (PMMA) as gate dielectric show a hole mobility of up to 2.2 cm2 V&#8722;1s&#8722;1 with a current ON/OFF ratio (Ion/Ioff) of 104∼105, with the mobility being two times larger than that of the spin-coated PDFDT based OTFTs. The higher mobility of the bar-coated PDFDT polymer films can be attributed to the well-organized fibril structures of the polymer chains. Importantly, two different molecular weight polymers (Mn = 23 and 34 kDa) were employed to conduct these experiments and both batches showed about the same performance, which mitigates the typical batch-to-batch variation in OTFT performance. Furthermore, we explored the operational stability of the bar-coated OTFTs in ambient air and nitrogen environments. The bias-stress and cycling tests between the ON/OFF states of the bar-coated devices showed high stability in both nitrogen and air. Conclusively, here we demonstrate that (i) a simple bar-coating process is a better method to control and obtain good polymer morphology in comparison to spin-coating, and (ii) the PDFDT polymer has great potential to provide good reproducibility and stability in large-area OTFT devices.Approved for entry into archive by Yoon HJ (hjyoon@kist.re.kr) on 2016-01-04T17:00:04Z (GMT) No. of bitstreams: 0Made available in DSpace on 2016-01-04T17:00:04Z (GMT). No. of bitstreams: 0
Previous issue date: 201602Organic electronicsOrganic thin-film transistorsConjugated polymersBar-coated high-performance organic thin-film transistors based on
ultrathin PDFDT polymer with molecular weight independenceArticle